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EZTV646 on Zazz Today for Radio Nerds $19.90 + $5.95 Delivery

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Hi All,

First time poster, but this is specifically for hardcore radio nerds. If you dont know what a software defined radio is, this bargain probably isn't for you.

A little while ago, a linux kernel hacker discovered that some usb TV tuners were capable of being modified at the software level to be used in a role as a software defined radio. Specifically, these were the ezcap eztv668 and eztv666, later this work was extended to included several others. However, ever since then these tuners have been quite tough to get (several people are now selling them on ebay specifically as SDR's - with an inflated price to go with it).

Heres a link to the article that describes the SDR work for these modules: http://sdr.osmocom.org/trac/wiki/rtl-sdr

I only post this bargain cause it got me excited and im sure I wouldn't be the only one who'd be interested in it for its SDR capabilities. The unit on zazz today is the eztv646 (which is also apparently capable of this mod) for $20 plus postage.

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  • Woo! Was looking for one of these on ebay after I noticed the RTL2832U hack.

  • +2

    http://en.wikipedia.org/wiki/Software-defined_radio

    OK this article explains a lot but what are you guys going to use this for exactly? :)

    • Well, there are scanners that enable you to listen listen to all kinds of radio comm's, from the Int'l Space Station to your local Ham (possibly in contact with ISS) or Burger King's wireless, not to mention your local very-costly-to-install-&-run "Government Radio Network" (for bushfire brigades, ambos, etc.)…

      but they cost from about $100:

      …to almost $500 or more, ie, to listen to the -next- (P25 digital) version of some "Gov't Radio Network" comm's, coming in a year; eg, cf:

      So, some see hacking a USB-based TV module as a way to reduce the cost, as well as "doing more with less" (using smarts & tips from the community to extend some widget's function-set ;-)

      The other reason people to this kind of thing is… 'cause we can. :-)

      Radio Hams - a.k.a. Amateur Radio hobbyist; cf http://www.WIA.org.au - love this kind of thing! Eg, some buy a UHF radio for their radio bands & make it work on Aussie's UHF CB channers (77 - 80 these days), so there can be a practical side that goes beyond saving $$$…

      …you get the idea. :-)

      • +1

        There is a little bit more to it then that. I used to be into ham radio (though these days im not that into it anymore) so i do have quite a bit of radio gear. Though the only thing that i even switch on these days is the icom ic-pcr1500 (fairly wide band black-box receiver thats totally controlled by software).

        the big diff between traditional radio and sdr's is in the way the signal is read or written. For example, my ic-pcr1500 does 100khz to 3.3Ghz with AM, FM and SSB because thats all the hardware supports. To explain a bit better, if i were 2day fm and i want to transmit my signal, there are two bits of hardware circuitry involved. one generates the carrier wave (106.9mhz) and another takes the audio i want to transmit and add's it to the carrier wave (modulation), in the case of 2day fm, my hardware needs to be able to create FM modulation.

        That has pretty much defined radio for a long time, two bits of hardware - one to generate the wave, another to generate the modulation.

        SDR though takes those components and moves them into software. In effect you get direct control over the wave on the antenna meaning your not limited by the modulations your hardware supports (AM, FM, SSB). For example, radio controlled planes used to use a modulation called PCM and PPM (pulse-code and pulse-position). No traditional radio would be capable of either sending or receiving those signals unless it has the hardware to encode/decode them. With the SDR however, I can write the modulation components in software to deal with both those (and it probably wouldnt be that hard) for both sending and receiving. I can even invent my own forms of modulation if I so wished.

        Basically, SDR's take radio's to a new level of control that no traditional radio can give you - this is what makes them a very interesting beast indeed. To date, they have one amazing quality - cost. Even a cheap software defined radio will cost you upwards of $1k and theres no upper limit.

        Those prices are falling quite rapidly at the moment though as people realise its not actually that hard to make one from various components so alot of "open" sdr projects have sprung up of late (though, these are still not cheap). One interesting use of these was a thing called openbts (in effect a SDR that can send/receive GSM cellular signals, entirely done within software) - http://en.wikipedia.org/wiki/OpenBTS worth a read.

  • Thanks for the post - picked one of these up on eBay when the news leaked, tempting to pick up another!

  • Can someone explain in one sentence wtf you can do with this?

    • +5

      You can pick up any transmissions in the frequency that the chip can receive. Traditionally, USB radios and TV receivers have decoded the frequency via hardware, so what is transmitted to the computer is a decoded signal already. SDR's decode the signals via software in your computer, so it passes the full range of what it receives into the computer to be decoded.

      In essence, if you have the right decoders, you can pick up on ANY kinds of transmissions, including wireless IPTV cameras, baby monitors, airport transmissions, fire/police transmissions, GPS signals and maybe even Wifi signals. It all just depends on the range of frequency that the hardware can detect.

      • I wonder if your rig will be as selective as it might need to be, eg, to keep pager interference out, when looking for the ISS or even earth station on 2m (144 - 148 MHz)?

        What sort of "front-end" circuit(s) are typically part of these TV units, when you buy them?

        (Not too fancy, from this one's $20 price, I'd guess… but who knows?)

  • For those interested, here's a reddit post talking about this: http://www.reddit.com/r/RTLSDR/comments/s2mad/for_aussies_ez…

  • My experience with Zazz products over the years has been less than impressive. I've purchased at least 10+ products and only 1 has lasted. Everything was cheap cr@p & poorly made.

    I've not purchased for over a year and I don't have this exact product, so I might be wrong and things might have changed, but I would steer clear of them. The quality on eBay from China would be no worse/better.

    • Mate, if you want "costly Aussie" rather than "Asian cheap" get yourself a WinRadio… I think they may have a S/W-Defined Radio (SDF) in their product range, by now… in fact, they may have had some for quite a while.

      'better have deep pockets when you order… :-/

    • Why did you purchase more than 10 products if they are so crap ?

  • I think police signals are encrypted and I think it's against the law to listen in on police communication. Please correct if i'm wrong

    • From what I remember back in England, it wasn't illegal to listen to police radio, but you were not allowed to act upon anything that you heard. They would often broadcast something silly like aliens landing in a field, then try and arrest anyone who turned up, as they were acting on what was said.
      Don't know if rules have changed, or if they're just different in this country.

      • Lots of US police channels still seem to be unencrypted (dunno if that's due to lack of $$$ to pay for encrypted radio systems or due to a desire for "transparency" in gov't, but I don't think I'd want to be a US LEO, knowing that gun-slinging baddies know when to expect my arrival to a crime scene).

        If you have an Android device, try "Scanner Radio" to listen… It gave some friends a bit of insight into "herd mentality" recently, after a basketball win in Lexington, KY brought riots to the town… lasting over a day! All on-display via their "Scanner Radio" app…

        Not pretty… :-/

  • Haven't tried software defined radios before but I used to love playing with CBs and Scanners. Bought one to have a play around with. You may have just started me on a new hobby :)

    If anyone has any more links for info on how to hack these please post. The more info the better.

  • OT: Something else for Nerds: "Revenge of the Nerds III" - a movie from a place & time, where/when nerds seemed to be quite in demand. :-)

  • just got one.. sounds fun and something to do.

    Thanks :D

  • +2

    DealExtreme have the EZTV668 model for ~$20 with free shipping.

    http://www.dealextreme.com/p/mini-dvb-t-digital-tv-usb-2-0-d…

    • +1

      If I understand what I've just been reading on the links, the better tuner is the Elonics E4000 which the Zazz unit doesn't have. The EZTV668 does have this so is perhaps a better deal. Just not sure if the standard software will support DAB+ radio like the software for the EZTV646 does.

      • Indeed, the 668 is supposedly a little better.. I didnt realise dx had them back in stock either. I'd been watching the wrong url (https://www.dealextreme.com/p/dvb-t-digital-tv-usb-dongle-st…) which lists them as sold out. If i'd seen them come back in stock, I probably would have got one of the 668's.

        I've had decent experiences with zazz (with returns) so not personally all that concerned really. TBH though, while this unit is capable of being an sdr, its not like its going to be amazing (either 646 or 668), it's something to experiment with and so i cant see myself caring much about the difference between the two.

  • Just got ezcap today… this gonna be fun :D

  • Anyone got theirs yet?

    • aaaaand one day after this post. i has it.

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